There exists a need for a flag device such as a dive flag that will remain extended at all times and perform various functions including as a warning device such as to identify the location where a diver is operating. Such a flag will remain relatively rigid and therefore highly visable under all conditions including under calm as well as during windy conditions. One of the problems with known flags including those used for the same and similar purposes is that they are for the most part constructed of a fabric or cloth-like material so that they hang limp under calm wind conditions and flap and flutter in the wind. Under both conditions the known flags are difficult to see especially from certain directions and at a distance. This is highly undesirable especially in areas where there may be considerable boating activity and where it is important to indicate where a diver is operating underwater so that boats and other vessels and water skiers in the area, and especially those traveling at relatively high speeds, will be able to see the flag in time to avoid the area. It is also important that flags of this nature be able to rotate with the wind to provide maximum visability and to indicate wind direction. There also exists a need for an improved float device for use with the subject flags, including a float device that is easy to install and use and one that does not become water-logged and will provide support for a swimmer including a swimmer equipped with snorkeling gear.